【Atlas 200 DK使用FAQ】模型输入时需要单通道图像如何处理

图片处理相关案例

问题描述：

原来是三通道的图像，但模型输入时需要单通道图像，这种情况下如何修改代码？

解决方法：

将原来的三通道图像转换为灰度图即可，代码示例如下：

bool face_emotion_inference::ImageYUV2BGR (
  const vector<ImageData<u_int8_t>> &resized_image,
  vector<Mat> &bgr_image) {
  for (vector<ImageData<u_int8_t>>::const_iterator resized_img_iter = resized_image.begin();
       resized_img_iter != resized_image.end(); ++resized_img_iter) {
  
    int img_height = resized_img_iter->height;
    int img_width = resized_img_iter->width;
    //std::cout<<"img height, img width"<<img_height<<"  "<<img_width<<std::endl;
    Mat src(img_height * kNv12SizeMolecule / kNv12SizeDenominator,
            img_width, CV_8UC1);
  
    int copy_size = img_width * img_height * kNv12SizeMolecule
                    / kNv12SizeDenominator;
    int destination_size = src.cols * src.rows * src.elemSize();
    int ret = memcpy_s(src.data, destination_size, resized_img_iter->data.get(),
                       copy_size);
    CHECK_MEM_OPERATOR_RESULTS(ret);
     
    Mat dst_temp;
    cvtColor(src, dst_temp, CV_YUV2BGR_NV12);
    Mat dst;
    dst_temp.convertTo(dst, CV_32FC3);
    //for(int i = 0; i < dst.rows; i++)
    //{
    //      for(int j = 0; j < dst.cols; j++)
            //{
                //std::cout<<"("<<dst.at<Vec3b>(i,j)[0]<<",";
                //std::cout<<dst.at<Vec3b>(i,j)[1]<<",";
                //std::cout<<dst.at<Vec3b>(i,j)[2]<<")";
            //}
            //std::cout<<std::endl;
    //}
    //imwrite("dst_temp.jpg", dst_temp);
    //imwrite("BGR.jpg",dst);
    //dst_temp = imread("face1.jpg");
    //dst_temp.convertTo(dst, CV_32FC3);
    bgr_image.push_back(dst);
  }
  return true;
}

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